**Author details**

straw that remains on the soil after the harvest of sugarcane not debrided with fire varies according to cultivar and adopted agricultural practices; such amount ranges from 12 to 18 t ha−1 [22]. In studies conducted by [22] in the region of Ribeirão Preto, SP, it was verified that, among the nutrients in straw, only potassium presented a great liberation during 1 year of permanence of this crop residue in field (**Table 12**). Thus, with the exception of K, the nutrients contained in straw will not contribute significantly to the nutrition of sugarcane during

Vinasse and filter cake are the main residues of cane industrialization. Vinasse, which has potassium, calcium, and organic matter as main constituents, is generally used for regrowth fertilizations and may, as discussed above, provide all the K for cultivation. According to the origin of the vinasse, the concentrations of the elements may vary, and chemical analyses must be conducted before its application. However, in general, the concentration of K in the vinasse originating from mixed must is, on average, twice as higher as that obtained from

Filter cake has a high percentage of moisture (approximately 75%), and average levels of P and Ca vary, respectively, from 5.0 to 10 and from 15 to 36 kg per ton of dry matter. It is used mainly in plant cane fertilization, applied at the bottom of the planting groove at an average dose of 30 t of natural matter per ha, or in total area at twice the dose. Considering an application of 40 t of natural filter cake per ha, around 10 t dry matter, with an average content of 7.0 kg of P per t of dry matter, there is a contribution of 70 kg of P per ha, dispensing phos-

The composting of organic residues, mainly of sugarcane bagasse, is one more option for the use of such residues in the fertilization of sugarcane and in the improvement of the physical and chemical properties of the soil. The authors evaluated the technical and economic feasibility of using organic compounds based on sugarcane bagasse in sugarcane plantation. The research was conducted in soils with a great physical heterogeneity and a high capacity of phosphorus adsorption. Different mixtures of sugarcane bagasse and chicken litter were tested, ranging from 100 kg of bagasse to 80 kg of bagasse +20 kg of chicken litter, plus

**Hemicellulose Cellulose Lignin Cell content C/N C/S C/P**

**N P K Ca Mg S C**

Source: Oliveira et al. [22]. Values followed by the same letter are not significantly different (Tukey's test) at the 0.05 level.

**Table 12.** Mass of dry matter (DM), amount of nutrients and structural carbohydrates in the samples of freshly harvested

1996 3.747 a 5.376 a 1.043 a 3.227 a 97 a 695 a 947 a 1997 943 b 5.619 a 1.053 a 2.961 b 68 b 455 b 552 b

1996 13.9 a 64 a 6.6 a 66 a 25 a 13 a 9 a 6.255 a 1997 10.8 b 53 a 6.6 a 10 b 14 8 b 8 a 3.642 b

sugarcane straw without burning (1996) and in the remaining straw 1 year later (1997).

broth, with values ranging from 2.5 and 1.2 kg m−3, respectively.

phate fertilization at the time of planting for most soils.

**Year Structural carbohydrates (kg ha−1)**

**Year DM (t ha−1) Nutrient (kg ha−1)**

the cycle following the cut.

188 Sugarcane - Technology and Research

Mauro Wagner de Oliveira<sup>1</sup> , Geraldo Antônio Resende Macêdo2 , Jolberto Alves Martins3 , Vinicius Santos Gomes da Silva1 and Alexandre Bosco de Oliveira4 \*

